1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Cylinder number 4 and fuel bank 1 locations?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Jason Ohler, Aug 7, 2014.

  1. Jason Ohler

    Jason Ohler New Member

    Joined:
    Aug 7, 2014
    5
    0
    0
    Location:
    Cumberland Md
    Vehicle:
    2006 Prius
    Model:
    N/A
    Ok, I'm new to this so here goes. having some idling issues. Pulled codes P0172 and P0304. Basically running rich on fuel bank 1 and misfire on cylinder number 4. My question is what is the locations of each...? From what I have read number 4 cylinder is closest to the drivers side and fuel bank 1 is on the passengers side. I have changed the MAF, plugs and checked the ignition coils. All looks to be good. I am guessing possibly fuel injector?
     
    #1 Jason Ohler, Aug 7, 2014
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,200
    6,482
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    You are right that cylinder 4 is closest to the driver's side.

    DTC P0172 means that the air/fuel ratio is too rich. The reference to bank 1, sensor 1 simply means that the issue can be with the upstream air/fuel ratio sensor. There is only one bank. Some cars have dual exhaust and such vehicles would have a bank 1 and a bank 2.

    What did the old spark plug in cylinder 4 look like and how did it compare to the other three plugs?

    If cylinder 4 showed a very dark plug, that would be an indication of an overly rich fuel mixture and the fuel injector would be a reasonable candidate to suspect.
     
    #2 Patrick Wong, Aug 7, 2014
  3. valde3

    valde3 Senior Member

    Joined:
    Jun 28, 2014
    2,002
    745
    0
    Location:
    Finland
    Vehicle:
    2004 Prius
    I think that the misfire can cause rich running code. By letting unburned fuel into exhaust. So fault may also be with ignition system. Easiest check would be to swap ignition coil from cylinder 4 with ignition coil of another cylinder. If misfire moves with coil then coil is faulty. If it doesn’t then problem can be with fuel system, rest of ignition system, or mechanical.
     
    #3 valde3, Aug 8, 2014
  4. Jason Ohler

    Jason Ohler New Member

    Joined:
    Aug 7, 2014
    5
    0
    0
    Location:
    Cumberland Md
    Vehicle:
    2006 Prius
    Model:
    N/A
    I tried the swap but have not gotten any misfire codes to come up since" I am still getting the the running rich code. Here's my question though if Imam miss firing on cylinder 4 wouldn't I be getting a bank 2 running rich fault code not 1 as the are on opposite end of the engine? Or am I'm I incorrect on this?
     
    #4 Jason Ohler, Aug 8, 2014
  5. valde3

    valde3 Senior Member

    Joined:
    Jun 28, 2014
    2,002
    745
    0
    Location:
    Finland
    Vehicle:
    2004 Prius
    Prius engine has only one bank. Bank1 all 4 cylinders belong to that one bank.

    Normally inline four cylinder engines have only one bank. And in rare cases they have two its cylinders 1 and 4 in bank1 and cylinders 2 and 3 in bank2

    So rich code did come back but misfire didn’t? Did all old plugs look the same?
     
    #5 valde3, Aug 8, 2014
  6. Jason Ohler

    Jason Ohler New Member

    Joined:
    Aug 7, 2014
    5
    0
    0
    Location:
    Cumberland Md
    Vehicle:
    2006 Prius
    Model:
    N/A
    Well that makes alot more sense to me then. So there is a very good possibity the misfire code on cylinder number 4 could be from a faulty injector that corrosponds to that cyclinder. I will have to look at the plugs this eve to see how they look. I had originally changed the plugs when this issue started but did not see any indication of it running rich...My last question is where is number 4 cylinder located. I am assuming the on nearest the drivers side?
     
    #6 Jason Ohler, Aug 8, 2014
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,200
    6,482
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Your question was answered in my post #2 above. Yes, cylinder 4 is at the "rear" of the engine and is closest to the driver's side.
     
    #7 Patrick Wong, Aug 8, 2014
  8. Jason Ohler

    Jason Ohler New Member

    Joined:
    Aug 7, 2014
    5
    0
    0
    Location:
    Cumberland Md
    Vehicle:
    2006 Prius
    Model:
    N/A
    sorry missed that. thanks for your help.
     
    #8 Jason Ohler, Aug 8, 2014
  9. Macs

    Macs Junior Member

    Joined:
    Apr 4, 2020
    13
    2
    0
    Location:
    NY
    Vehicle:
    2010 Prius
    Model:
    IV
    Jason, any updates? Did you check or change the injector at cylinder #4?
     
    #9 Macs, Dec 27, 2020
(You must log in or sign up to post here.)